Carriage shifting mechanism



July 7, 1953 v N. F. HAWTHORNE 2,644,639

CARRIAGE SHIFTING MECHANISM Filed Aug. 15, 1950 I 7 Sheets-Sheet 1GDCUJB2 Ci) FIIE L 4 INVEN TOR. NATHANIEL E HAWTHORNE July 7, 1953 N. F.HAWTHORNE 2,644,639

CARRIAGE SHIFTING MECHANISM Filed Aug. 15, 1950 7 Sheets-Sheet 2 r '7FIE-2 IN V EN TOR. NATHANIEL F. HAWTHORNE y 7, 1953 N. F. HAWTHORNE2,644,639

CARRIAGE SHIFTING MECHANISM Filed Aug. 15, 1950 '7 Sheets-Sheet 3 IN VEN TOR. NATHANIEL HAWTHORNE July 7, 1953 N. F. HAWTHORNE 2,644,639

CARRIAGE SHIFTING MECHANISM Filed Aug. 15. 1950 7 Sheets-Sheet 4 July 7,1953 Filed Aug. 15, 1950 N. F. HAWTHORNE CARRIAGE SHIFTING MECHANISM 7Sheets-Sheet 5 IN V EN TOR.

V NATHANIEL F. HAWTHORNE BY July 7, 1953 N. F. HAWTHORNE CARRIAGESHIFTING MECHANISM,

Filed Aug. 15, 1950 7 Sheets-Sheet 6 R. NATHANIEL F. HAWTHORNE.

l mNVEN T0 NL MHHH y 7, 1953 N. F. HAWTHORNE 2,644,639

CARRIAGE SHIFTING MECHANISM Filed Aug. 15, 1950 7 Sheets-Sheet 7 sec ij" 358 3|3 sea ii am 369 3" I28 ll an FIE-E PIE 5 7 see 2 as; see

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"[{ll/l/MN INVENTOR. NATHANIEL F. HAWTHORNE Patented July 7, 1953CARRIAGE SHIFTING MECHANISM Nathaniel F. Hawthorne, Alameda, Calit,assignor to Friden Calculating Machine Co., Inc., a corporation ofCalifornia Application August 15, 1950, Serial No. 179,479

This invention relates to calculatingmachines, and is more particularlyconcerned with the provision of improved mechanism for shifting theregister carriage thereof selectively in either direction. a

It is an important object of the .present invention, therefore, toprovide for the register carriage of a calculating machine anordinalshifting mechanism which is. relatively smooth and quiet inoperation even though: the carriage shifting operation is power-operatedand is performed at a relatively rapid rate of speed,

It is also an object of the invention to produce an improved. mechanismfor ordinally shifting the register carriage of a calculating machineselectively in either direction by a relatively smooth shiftingmovement, which mechanism is also operable to terminate the shiftingmovement of the carriage in any desired ordinal position Without causingobjectionable noise'or vibration.

It is another object of the invention to provide a mechanism forsmoothly and quietlyterminating high speed shifting movement of theordinally shiftable carriage in a calculating machine, which mechanismis also, operable to prevent overtravel of such a shiftable registercarriage beyond its true ordinal position by positively locking the samecentrally in the selected ordinal position as soon as the desiredshifting movement thereof has been completed.

. It is also an object of the invention to produce a relatively quietand vibration-free mechanism for positively stopping the ordinalshifting movement of a calculating machine carriage in'such a manner asto substantiall prevent inertia forces from. causing overtravel of thecarriage beyond its selected ordinal position.

Further objects are. to provide a construction of maximum simplicity,economy, and ease of assembly and disassembly, also such furtherobjects, advantages and capabilities as will fully appear and as areinherently possessed by the device and invention described herein. I

The invention further resides in the combination, construction andarrangement of parts illustrated in the accompanying drawings, and whilethere is shown therein a preferred embodiment thereof, it is to beunderstood that the same is illustrative of the invention; and that theinvention is capableof modification andlchangeand 9 Claims. (01. 235-63)comprehends other details of construction without departing from thespirit thereof or the scope of the appended claims.

Referring to the drawings:

Fig. 1 is a plan view of a standard Friden calculating machine showingthe keyboard and control panel arrangement thereof.

Fig. 2 is a sectional view of the carriage shift mechanism taken alongthe lines 22 in Fig. 6 and looking in the direction of the arrows.

Fig. 3 is a right side view of the control plate taken along the lines3-3 in Fig. 5, showing the switch and main clutch control mechanisms.

Fig. 4 is a detailed elevational view of the shift control mechanismtaken along lines 44 in Fig. 5 and looking in the direction of thearrows.

Fig. 5 Ba plan view of the machine with certain parts removed to moreclearly show the construction and arrangement of the carriage shiftcontrol mechanism.

Fig. 6 is an enlarged rear view of the positive shift stoppingmechanism.

Fig, 7 is a sectional view taken along the lines 1-! in Fig. 2 showingdetails of the carriage shifting mechanism.

Fig. 8 is an enlarged plan view showing details of the shift controlmechanism.

Fig. 9 is an elevation view taken along the lines 9-9 in Fig. 6 showingdetails of the control cam associated with the carriage stoppingmechanism.

Fig. 10 is a cross-sectional view of a portion of the control cammechanism shown in Fig. 9.

General arrangement The calculating machine selected for illustration inconjunction with the instant invention is of the general type describedin the patent to Carl M. Friden No. 2,315,780, issued April 6, 1943,wherein similar parts are identified by the same reference numerals asin the present disclosure. The general arrangement and operation of sucha standard Friden calculating machine is well known, and includes ashiftable register carriage 22, shown in Figs. 1 and 2, which serves tomount the numeral wheels of a revolutions counter 4! (Fig.1) having asuitable actuating and tenstransfer means such as is described in PatentNo. 2,229,889, issued to Carl M. Friden on January 28, 1941. Thiscarriage 22 also mounts a plur'ality of ordinally arranged accumulatordials 3| provided with a tens-transfer mechanism of known design, whichdials 3I are suitably journalled in carriage 22 and are adapted foractuation through suitable plus-minus gearing 13, 14 (Fig. 2) having asliding driving engagement with a square shaft 'II in each order and areversing engagement with a pinion gear 33 secured to the lower end ofeach of the accumulator dial shafts 32. As is fully shown and describedin the afore-mentioned Friden Patent No. 2,3 15,180, a pair of valueselecting gears are slidably supported for rotation with the squareactuating shafts H in each order, which gears receive from theirassociated selection slides differential increments of movement whichbear a predetermined relationship to the value of the keyboard amountkey i (Fig. l) which has been depressed in that order. Hence, the.stepped teeth on the associated actuating cylinders 54. (Fig. 5) rotatethe corresponding square shafts II to an extent amount keys 5| whichhave been depressed. The

sign character of registration for the accumu- I later register dials 3Iis controlled by shifting the plus-minus gearing 13, 14 under control ofa strap or gate 15 mounted by suitable upright arms on a transverserockable shaft 16 (Figs. 2 and 5) which may be controlled by therespective plus and minus keys 300, 30! (Fig. l) or in any otherconvenient manner in performing calculating operations.

As shown in Figs. 3 and 5,,transverse drive shaft 58 and the associatedunidirectional actuating shafts 51 are driven cyclically from a suitableelectric motor through main clutch 6I (Figs. 3 and 5) which is driven bysuitable gearing 02 from the motor output shaft 63. Clutch BI is engagedor disengaged by the pivotal movement of a clutch control lever 61 (Fig.3) which is pivotally mounted on the side plate of the machine. Duringrotation of this main clutch, control lever 61 and the parts associatedtherewith are maintained in active position by a roller 58 carried bylever 61 and adapted for engagement with the periphery of the clutch 6|in such a manner that the control lever 61 can only move to clutchdisengaging position whenever the machine is in the full-cycle position,as is fully shown and described in Patent No. 2,229,889, issued to CarlM. Friden on January 28, 1941.

Carriage shifting mechanism Means are provided for shifting the carriagein either direction from one ordinal position to another by power-drivenmeans controlled by manually operable keys. For this purpose carriage 22is provided with a rack 82 (Figs. 6 and 7) suitably mounted along therear edge thereof, which rack 82 has a plurality of involute gear shiftteeth 83 formed in the lower edge thereof and spaced apart a distanceequal to the ordinal spacing of the machine. These rack teeth 83 areadapted to engage with the similarly shaped involute teeth 85 on acoacting -tooth carriage shift gear 303, journalled in rear bearingplate 329 and rear frame bracket 392 affixed thereto, and rotated bymeans to be hereinafter described so as to effect a lateral shiftingmovement of the carriage. Thus, a one-fourth or 90 rotation of thecarriage shift gear 303 moves rack 82 laterally so as to effect oneordinal movement of the shiftable carriage 22. At its ends the shiftrack 82 is provided with a pair of oppositely disposed yieldable pawls,not shown, which are 4 adapted to be rocked by the pins 302 on theinvolute gear teeth (Fig. 7) against an associated return spring so asto prevent the attempted shifting of the register carriage beyond thelowest and highest ordinal positions thereof, as is fully shown anddescribed in Carl M. Friden Patent No. 2,294,083, issued August 25,1942.

In order to rotate the carriage shift gear 303 in either direction byselectively operable drive connections from the actuating means of themachine, the lowest order actuating shafts 51 (Fig. 5) are extendedrearwardly and have respective shift clutch drivers 30!, preferably ofthe type shown and described in Morton P. Matthew application S. N.180,584, filed August 21.

1950, which drivers are pivotally connected to the ends of the adjacentshafts 51 in such a manner as to form a readily controllable clutchingand declutching engagement with the associated clutch followerassemblies 305 on the respective gear sleeves I01, I02. Gear sleeve IOIis provided with a gearI03 which meshes with a driven gear I04 on theintermediate gear assembly 306 (Fig. 7) Gear sleeve I02 has offsetaxially from gear I04 a. gear I06 which meshes with a relatively widereverse idler gear I01 suitably journalled on theframe and. meshingwiththe gear I04. This gear I 04 forms partof the unitary compound gearassembly 306 (Figs. 2 and 7) which also includes the short shaft 301 anda smaller concentric gear 300 adapted to engage with a shift drive gear309. mounted on a short drive shaft 3 I 0 which is connected atits otherend to the carriage shift gear 303. Thus, rotation of the gear sleevesIN and I02 in a clockwise direction, as viewed in Fig. '7, causesshifting of the carriage 22 to the right and to the left, respectively,as viewed from the rear of the calculating machine.

Manually operable control means are provided to enable shifting thecarriage in either direction through one or more ordinal spaces. Shiftkeys III, II2 (Figs. 1, 3 and 4) are depressible to initiate shifting ofthe carriage to the right and left, respectively, as viewed from thefront of the machine (to the left and right, respectively, in Fig. 6).Depression of either shift key III, II2 serves to enable the associateddrive connection as well as to engage the clutch and energize the motor.Keys III and H2 are suitably mounted for endwise movement on the frameplate I3 and carry respective pins H3 associated with lever I I 4 (Fig.3) pivotedon the frame plate I3. 7 One part of lever I I4 has inclinedcam slots I I5 arranged for cooperation with the respective pins 3-Lever [I4 is connected by link II1 with the clutch control lever 61(Fig. 3) so that themain clutch IiI' is engaged upon depression ofeither shift key. At its lower end lever H4 is pivotally'connected withlever 8' also suitably pivoted on the frame and carrying an insulatedpin II9 operatively related to close the contacts I20 of the motorcircuit upon depression of either shift key.

To enable the respective drive connections from the actuating shafts 51to the carriage shifting mechanism upon depression of a shift key, therespective pins I I3 (Fig. 4) overlie levers IN and I22 secured onconcentric sleeve I24 and shaft I23. Shaft I23 and sleeve I24 carrysimilar depending arms I25 and I21, respectively, (Figs. 4 and 5) havingtheir lower ends disposed in front of the respective shift control rodsI28 and I29,- which rods have return springs I3I associated therewith tomaintain themnormally in inactive position. At their rearward ends, eachof the rods I28 and I29 carries a controller 3 adapted to ooact with theassociated shift clutch driver 304 so that upon depression of eithershift key II I, II2 the associated drive connection is established,preferably as described in Morton P. Matthew application S. N. 180,584,filed August 21, 1950, at the same time that the main clutch 6| isengaged and the motor is energized. Thus, by the selective depression ofshift keys II! and H2, carriage shift gear 303 can be rotated in eitherdirection to effect ordinal shifting of the carriage.

Shift stopping mechanism Mechanism is provided for smoothly stopping andterminating the carriage shift by positively arrestin the forwardmovement of the shiftable carriage before the inertia forces actingthereon have carried the carriage beyond its home or selected ordinalposition. The carriage stopping mechanism now to be described does notrely upon springs to perform the mechanical work required for stoppingthe lateral shifting movement of the carriage, thereby substantiallyreducing the load on the shift drive mechanism and substantiallyeliminating any tendency of the carriage to pull ahead of the shiftdrive, with the result that a smooth and relatively quiet carriageshifting action is achieved during both single and multiple ordershifting operations. It will be recalled that as the shift keys I I I, II2 are selectively depressed the corresponding clutch driver 304 isengaged with its associated clutch follower assembly 305 (Fig. 5) andthe main clutchlil and switch contacts I20 are closed so that thecarriage 22 is shifted laterally as desired. The shift control rods I28,I29 are provided at their rear ends with shift controllers 3H (Figs. 2and 8), each having thereon a forwardly extending clutch disengaging dog3l2, an angularly outwardly extendin clutch engaging ear 3I3, and adownwardly disposed vertical shove dog 3I4 (see also Fig. 2). As thecontroller all associated with left shift control rod 528 is movedrearwardly to effect engagement of the respective clutch driver 304 withthe associated shift clutch follower assembly 305 (Fig. 5), thedownwardly depending shove dog 314 thereon act through an interponentarm 360 on bellcrank 36I (Fig. 8) to move rearwardly a shift release camcontrol pin 334. This bellcrank 256i is pivotally supported as at 332 ona right angle bracket extension 353 carried by the rear bearing plate ofthe machine. The rearwardly extending arm of bellcrank 36I is pivotallyconnected at 365 to one end of an interconnecting link 366 (Figs. 6, 7and 8) having its other end pivoted at 361 on another bellcrank 368fulcrumed at 369 on a right angle support bracket 313 secured to therear bearing plate 329. An arm 3' extending laterally outwardly frombellcrank 368 is adapted to coact with the downwardly depending shovedog 3 I4 on the controller 3| I associated with shift control rod I29.Hence, bellcranks 3BI, 368 are simultaneously rocked whenever shiftcontrol rod I28 or I29 is moved rearwardly so as to close the normallyopen shift clutch by engaging the associated shift clutch driver 384with the immediately adjacent shift clutch follower assembly 335 (Figs.2 and 5). Also pivoted at 312 on a rigth angle bracket 313 suitablysecured to the rear bearing plate 329 is a shift interlock lever 314(Figs. '7 and 8) having its opposin ends adapted to coact withthecontroller shove dogs 3| 4 associated with the respective shift controlrods I28, I29 so that only one such control rod can be moved rearwardlyto shift clutch engaging position at a time. It will thus be apparentthat as right shift control rod I29 is moved rearwardly the bellcranks368, 36I are rocked counterclockwise (Fig. 8) so that arm 360 onbellcrank 36! moves cam control pin 364 rearwardly in the same manner asis directly caused by the rearward movement of left shift control. rodI28 (Fig. 8).

Referring now to Figs. 6 and 9, it will be observed that cam control pin364 extends through and projects beyond suitably aligned holes in therear bearing plate 329 and in a parallel rear backing plate 318 affixedthereto and suitably-spaced therefrom. This pin 364 is supported forfree axial movement by the plate; 329, 378. The pin carries an upwardlyextending shift yoke 318, the bifurcated upper end of which engages witha suitable annular recess 383 (Figs. 5 and 9) in a shiftable collar 38Iwhich is slidably and rotatably journalled in the plates 323, 318.Collar 33! is also disposed concentric with the axis of a rearwardlyextending drive shaft 382 which is provided on the third order actuatorshaft, and collar MI is provided at its rearward end with a shiftrelease cam 383. The cam and collar are urged inwardly as a unit by thehelical compression spring 384 so as to normally retain plate cam 383out of the plane of its associated cam follower 385. A coupling dog 386(Figs. 5 and 9) on shaft 382 is gripped by corresponding slots in collar38! so as to form a slidin but constant torque transmitting engagementbetween the actuator shaft extension 382 and the shiftable collar 38!which carries the plate 383. Hence, cam 383 rotates with shaft 382 atall times, not only when the cam is urged forwardly to its normallyineffective position by spring 384, but also Whenever pin 365 and shiftplate 379 move collar 384 rearwardly to bring plate cam 383, against thecompression of spring 384, into its active position within the plane ofthe cam follower 385, as shown in Fig. 9.

Referring now to Figs. 2 and 6, cam follower 385 is supported by one armofa lever 38'! which is pivoted at 388. Lever 38'l has a bifurcatedouter end 388 Which engages a pin 398 on a vertically movable slideplate 39I slidably supported on the rear frame bracket 382 by thepin-andslot connection 393 and the strap plate 394. A tension spring 395having one end secured to a pin 396 on slide plate 39I and its other endanchored to a pin 31'! on strap plate 394 tends to urge slide plate 39Iupwardly against its resilient limiting stop 403 (Fig. 6) so that thepin 39? provided at the upper end of slide plate 39I is urged into acoacting slot 338 provided in the carriage stop rack 438. This stoprack, which is secured to the shiftable carriage 22 in a positionsubstantially parallel to the shift rack 82 (Figs. 2 and 6), is providedwith a plurality of ordinally spaced grooves or slots 398 havingsuitably rounded or chamfercd outer edges 4!!I (Fig. 6) joined by adepressed curved portion formed substantially to the configuration ofthe coacting stop pin 39? on slide 39L Although the linear spacing ofthe slots or grooves 398 corresponds to that of the involute teeth 83 onshift rack 82, these slots have a staggered relationship withrespectthereto, so that the slots are substantially symmetricallydisposed with respect to the vertical axis of the involute teeth 33 onrack 82. A substantially fiat horizontal edge 432 (Fig. 6) joins the 9chamfered edges 40! and extends laterally between adjacent slots 398.

The shape of the shift release cam 333 (Fig. 6) is such that the highpoint 404 of the cam is positioned immediately adjacent to but not incontact with the cam follower 385 whenever the machine is in thefull-cycle position shown in Fig. 6, at which time the carriage stopslide 391 is in its uppermost position and the stop pin 39'! is retainedby spring 395 in intimate contact with the coacting slot 398 in thecarriage stop rack 40!). Whenever one of the shift control rods I28, I29is moved rearwardly, however, so as to close the. associated shiftclutch and move the controller shove dog 314 into operative engagementwith the associated bellcranl: 381 or 398 (Fig. 8), in the mannerpreviously described, the camcontrol' pin is also moved rearwardly. Therearward movement thus imparted to pin 39 1 acts through shift, plate319 to move collar 99! rearwa'rdly (Fig. 9), thereby moving the shiftrelease cam 383 into the plane of the cam follower 385 on the shiftrelease lever 381. At the beginning of the shift cycle the high point 49of cam 383 moves into engagement with roller 385 so as to rock lever 381counter-clockwise (Fig. 6), thereby depressing slide 39: so that thestop pin 391 carried thereby is moved out of engagement with thecoacting slot 393 on the carriage stop rack 400. The Matthew clutchshown herein, and the use of which is preferred in connection with myinvention, has a lag of about from the beginning of rotation of theactuator shafts 51 and 382 before the clutch driver 304 engages theclutch follower 36-5. period of lag in the clutch, the cam 383 will haverotated approximately 15 and therefore the high point 404 will haveengaged cam follower roller 385 and rocked lever 381 to its extremecounter-clockwise position. In this position the pin 391 will becompletely withdrawn from the coacting slot 398. Thus, during the firstfew degrees of movement of the actuator shafts, and before the shiftclutch begins to shift the carriage, the pin 39'! is disengaged from theslot 398. At approximately half way through the cycle the gradual dropof the cam from its high point 593 to its low point 399 will permit theslide 39! to rise under the force of its spring 395. Thus, atapproximately the midpoint of a cycle the pin 391 will come intointimate contact with the coacting horizontal surface 482 betweenadjacent slots, and thereafter the rack 499 will slide along the pin391' as the carriage shifts to the next ordinal position. In a singlecycle shifting operation, or in the last shifting cycle of a multipleorder shifting operation, the pin 391 will enter the chamfered edge 40!of the next adjacent slot, shortly before the end of the cycle,whereupon the spring 395 will snap the pin 391 into the slot 398 andpositively centralize the carriage. In this manner the pin 391 ispositioned into the next ordinal recess 398 to terminate the carriageshift before the inertia of the shiftable carriage can cause it totravel beyond its ordinal position.

During a multiple order shifting operation the stop pin 391 will beprevented from moving into the slot 398, so that the shift will benoiseless and smooth. It will be recalled that the cam 383 is preferablyabout 15 ahead of the operation of the shift clutch. Therefore in eachordinal stepping of the carriage the pin 39? will be enabled to engagethe horizontal edge 492 of the centralizing rack 400 at approximatelythe midpoint of the cycle, as before. However, the high point 404 Duringthis of the cam 383 will again rock the arm 381 (counter-clockwise, Fig.6) at approximately the instant when the pin 391 approaches the leadingchamfered edge 40.]. Thus, the slide 39I and pin 39.1 are rockeddownwardly away from rack 408 the instant before the pin 391 wouldnormally be thrust into the slot 398. By this means the pin 391 isprevented from centralizing the carriage at each ordinal step of amultiorder shift. However, in the final cycle, as the shift rods I28 orI29 will have been released, thereby permitting the cam 383 to be pushedout of the plane of roller 385, prior to the end of a cycle, the pinwill be enabled to enter the associated slot 398 at the proper time.

It will also be observed that spring 395 performs no centralizing work,but that this spring tends. to enable active positive engagement betweenthetop pin 391 and the coacting slots 398 on the carriage stop rack 409.Hence, spring 395 imposes substantially no additional load on the clutchdriving and driven members or other components of the carriage shiftingmechanism, and substantially eliminates any tendency of the shiftablecarriage 22 to pull ahead of the associated carriage shift drive.

I claim:

1. In a calculating machine having a frame, a shiftable registercarriage, means for shifting the said carriage including a shift rackmounted on the said carriage and a rotatable gear assembly mounted onsaid frame and meshing with said rack, and cyclically operable powermeans, connecting means for driving the said gear assembly and the saidcarriage selectively in either direction by said power means, a controldevice for controlling operation of said connecting. means, acentralizing mechanism for the said carriage in cluding an ordinallyslotted stop plate on the said carriage and a coacting stopping memberon the said frame, resilient means for biasing the said stopping memberinto carriage centralizing engagement With the said stop plate, meansfor disabling the said centralizing mechanism by moving the said slideout of the range of the said stop plate, and means controlled by saidcontrol devicev for connecting said disabling means to said power meansimmediately prior to operation of said connecting means to effectshifting of said carriage.

2. In a calculating machine having a frame, a shiftable registercarriage, means for shifting the said carriage including a shift rack onthe said carriage and a reversible gear assembly mounted on said frameand meshing with said rack, driving means including a normally openshift clutch adapted to be closed to cause the said gear assembly toshift the said carriage laterally in the desired direction and a shiftclutch control member, a centralizing and stopping mechanism for thesaid carriage including an ordinally slotted stop plate on the saidcarriage and coacting stopping slide on the said frame, the said slidebeing normally spring-urged into shift stopping and centralizingengagement with the said stop plate, cam-operated means operable towithdraw the .said slide from engagement with said plate, and meanspositioned by said clutch control member for operatively connecting saidcamoperated means to said driving means prior to the operation of saidclutch.

3. In a calculating machine, the combination which comprises a shiftableregister carriage, a shift operating rack and a stop plate on saidcarriage, the said stop plate having ordinally 9 spaced slots thereoncorresponding to the teeth of the said rack, a reversible carriage drivegear assembly for operating the said shiftoperating rack, driving meansincluding a shift clutch operable to cause the said reversible gearassembly to shift the said carriage laterally in the desired direction,a clutch control member for operating said shift clutch, a lockingmember normally positioned and maintained in positive stopping andlocking engagement with a predetermined one of the said slots so as tostop and retain the shiftable carriage in its selected ordinalposition,and mechanism controlled by the clutch control member and driven by saiddriving means for moving the said locking member out of the operativerange of the said stop plate prior to the closing of the shift clutch.

4. In a calculating machine, the combination which comprises a shiftableregister carriage provided with a shift operating rack and a stop plate,the said stop plate having ordinally spaced slots thereon, a reversiblecarriage drive gear assembly for operatng the said shift rack, drivingmeans including a pair of normally open shift clutches adapted to beselectively closed to cause the said reversible gear assembly to shiftthe said carriage laterally in either direction, a control member foreach clutch, a shift control member normally maintained in activeengagement with the slots of said slotted stop plate, a

withdrawing mechanism operable to move said shift control member fromengagement with said stop plate, and an interponent operated by eitherof said clutch control members for operatively connecting saidlast-mentioned mechanism to said driving means prior to the operation ofthe respective clutch.

5. In a calculating machine, the combination which comprises a shiftableregister carriage provided with a longitudinal shift rack and a stopplate disposed substantially parallel therewith, the said stop platehaving ordinally spaced slots thereon corresponding to the teeth on thesaid shift rack, a reversible gear carriage drive assembly for operatingthe said shift rack, driving means including a pair of normally openshift clutches having a lost motion connection therein and adapted to beselectively closed to cause the said reversible gear assembly to shiftthe said carriage laterally in either direction, a clutch J controlmember for each such clutch, a positionable shift control membernormally maintained in positive engagement with a predetermined slot inthe associated stop plate for terminating the carriage shifting movementin the selected ordinal position, a normally disconnected mechanismcyclically operated by the said driving means for moving the said shiftcontrol member out of engagement with the slots of said stop plate, andmeans operated by either of said clutch control members for operativelyconnecting said mechanism to said shift control member prior to theoperation of its respective clutch.

6. In a calculating machine, the combination which comprises a shiftableregister carriage, a longitudinally disposed shift operating rack on thesaid carriage, a longitudinally disposed stop plate supported on thesaid carriage having wide teeth and relatively narrow ordinally spacedvertical slots therebetween, the said slots being arranged to correspondwith the teeth on the said operating rack, a reversible gear carriagedrive assembly for operating the said shift rack, driving meansincluding a pair of normally open shift clutches adapted to beselectively closed for enabling the said reversible gear assembly toshift the said carriage laterally ineither direction, a verticallymovable shift control plate having a pin thereon adapted to be normallymaintained in shift stopping and locking engagement with a slot on thesaid stop plate corresponding to the selected ordinal position of thesaid carriage, and mechanism for moving the said control plate and pinthereon out of the operative range of the said stop rack as long as oneof the said shift clutches remains closed for controlling traverse of'the'said carriage during a shift operation. 1

7. In a calculating machine, the combination which comprises a shiftableregister carriage, a longitudinally disposed shift rack on the saidcarriage, a longitudinally disposed shift stop plate supported on thesaid carriage in parallel and spaced relationship wi h the said shiftrack, the said stop plate having relatively wide teeth provided withchamfered edges and relatively narrow tooth spaces therebetweencorresponding with and disposed symmetrically about the vertical axis ofthe teeth on the said shift rack, a reversible gear carriage driveassembly for operating the said shift rack, and driving means includinga pair of normally open shift clutches adapted to be selectively closedto cause the said reversible gear assembly to shift the said carriagelaterally in either direction, a vertically movable shift centralizingplate having a pin thereon adapted to be normally maintained in positiveshift stopping and locking engagement with a predetermined tooth spaceon the said stop plate corresponding with the selected ordinal positionof the said carriage, a lever for holding the said centralizing plate inan inactive position out of the range of the coacting tooth space on thesaid stop plate, and mechanism responsive to the movement of one of thesaid shift clutches to its closed position for moving the said lever andthe said centralizing plate to the said inactive position during acarriage shift operation.

8. In a calculating machine, the combination which comprises a frame, ashiftable register carriage mounted on said frame and provided with ashift operating rack and a shift stop plate, the said stop plate havingrelatively wide teeth and relatively narrow ordinally spaced verticalslots therebetween, a reversible gear carriage drive assembly foroperating the said shift rack, driving mechanism including normally openshift clutch adapted to be closed to cause the said reversible gearassembly to shift the said carriage laterally in a predetermineddirection, a shift control member vertically slidable on the said frameand having a sto pin secured to the upper portion thereof, a springnormally urging the said shift control member to an active positionwherein the said pin is moved into the coacting vertical slot in thesaid stop plate to establish a positive stopping and locking engagementtherewith, a lever operable to hold the said shift control member in aninactive position wherein the said pin is moved out of the range of thecoacting slots on the said stop plate during a shift operation, andmechanism operated by the said driving mechanism whenever the said shiftclutch is closed for retaining the said shift control member in itsinactive position during a carriage shift operation.

9. In a calculating machine having a frame, a shiftable registercarriage, means for shifting the said carriage in either direction,cyclically operable power means, connecting, means for connesting thesaid shifting means to said power means for operation of the shiftingmeansselectively in either-direction, a shift control member forcontrolling operation of said connecting means, a centralizing mechanismfor the said carriage including an ordinally slotted stop plate on thesaid carriage and :a coacting stopping member on the said frame,resilient power means normally urging the said member into ordinalcentralizing engagement with the said stop plate, means for withdrawingthe said slide out of the range of the said stop plate, and meancontrolled by said shift control member for connecting vsaidlast-mentioned" means to said power means immediately prior to operationof said connecting means.

NATHANIEL F. HAWTHORNE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 967,821 Naumann Aug. 16, 1910 1,970,512 Friden Aug. 14, 19342,216,636 Webb Oct. 1, 1940 2,313,817 Friclen Mar. 16, 1943 2,380,642Friden July '31, 1945

